It is the first 3D printing technology, appeared in 1986 and developed by 3D Systems.
Here, no nozzle or plastic wire, but an ultraviolet laser and a tank of liquid photopolymer. Like the filament deposition system, this process prints layer by layer. The laser hits the liquid that solidifies under the effect of ultraviolet. A tray immersed in the tray supports the solidified material and descends, as for the FDM, to go from one layer to the next.
Once the printing is complete, the object must be rinsed away from the remains of photopolymer with a solvent. The object is then baked to solidify it. A constraint that adds to the relatively slow process.
The usable materials remain rather few and despite the great precision offered by the SLA, this technique delivers relatively fragile objects. It is therefore limited to prototyping rather than the production of objects.
Last edited: 18/03/2019